The Climate Change Act, passed in 2009 by the Scottish Parliament, set binding targets to cut emissions for each year until 2020.

Christiana Figueres told BBC Scotland that, despite the Scottish government not meeting its interim targets, she was impressed by the pace of change.

She said the fact that emissions had been cut by 38% was "quite impressive".

Speaking to BBC Radio's Good Morning Scotland programme during a visit to Edinburgh, she said: "If we're moving back on the trend, that is not good, but we're moving forwards.

"We do know that Scotland has already been very exemplary to the world because it had all parties approving the 2009 act, with a 42% emissions cut target by 2020. We're already at 38%. That is actually quite impressive."

'Right direction'

She added: "The fact that Scotland is already producing 50% of its energy from renewable energies in this time frame is also very impressive.

"It's very much about the direction of movement here, the direction of travel, and that is undoubtedly the right direction of travel in Scotland."

In January, the Scottish government faced questions from the Committee on Climate Change, an independent statutory body advising the UK government and devolved administrations, over plans to cut spending on climate change by almost 10%.

However, committee member Prof Jim Skea of Imperial College, London, said the committee believed Scotland was still setting an example to other parts of the UK.

He added that there was room for improvement over the rate of planting forests and transport issues and said the Scottish government could do more in the area of low carbon heat, where no part of the UK was doing well.

Ms Figueres visited the Green Investment Bank in Edinburgh followed by a community climate project with Climate Change Minister Aileen McLeod.

She is due to meet First Minister Nicola Sturgeon at the Scottish Parliament later.